Actually, it seems to me that the ABC has another "nuclear option". Every document I've seen says that membership in the Anglican Communion, at least in part, is dependent on being in communion with the Archbishop of Canterbury. What then happens if he sends out a letter to all the Primates and to 815 that simply states, "I am no longer in communion with the Episcopal Church of the United States of America."?
More seriously, he does have that option and I suspect that if he exercised it against TEC and ACC (Anglican Church of Canada), he'd see his problems elsewhere (particularly in CofE) disappear rather quickly.
I suspect that would also increase the pressure from within at least some of the Continuing churches to rejoin the wwAC. (I am certain that would occur in my province.)